Guinea-Bissau is among the world's least developed nations and depends mainly on agriculture and fishing. Nearly 80 percent of the workforce is engaged in agriculture. Cashew nuts are by far the largest export; fish, seafood, peanuts, palm kernels, and timber are also exported. Imports include foodstuffs, machinery, transportation equipment, and petroleum products. The country's mineral resources, including phosphates, bauxite, granite, and limestone, are largely unexploited; however, prospecting for offshore petroleum deposits has begun. Industrial activity is mostly limited to the processing of agricultural products. Guinea-Bissaus main trading partners are India, Italy, Senegal, Nigeria, and Portugal.